HOXB9 is more abundant in human high-grade PCa tissues which harbour ALDH+ CD44+ CXCR4+ CD24+ subpopulation and silencing HOXB9 enhanced the sensitivity to various chemotherapeutic agents and decreased the metastatic ability of ALDH+CD44+CXCR4+CD24+ cells. This evidence concerns the gene CXCR4 and posterior cortical atrophy.